LONDON--Women who have persistent elevations in the serum marker CA 125 may be at substantially increased risk for ovarian cancer, a large study of women in the United Kingdom has shown.
Ian Jacobs, MD, of St. Bartholomew's Hospital, London, and his coinvestigators at Harvard, found that the use of serial CA 125 measurements, with the addition of ultrasound when indicated, was an acceptable and highly specific method of screening women for ovarian cancer.
The researchers caution that clinical application of the method would be premature, with the possible exception of women who are at very high risk, ie, those who have a strong, confirmed family history or who carry a mutation of the BRCA1 gene.
Their study included 22,000 asympto-matic postmenopausal women over age 45 who underwent baseline CA 125 screening and then were randomized to be followed with no additional CA 125 screening or with annual screening for 3 more years.
Women who had elevated CA 125 levels (greater than 30 U/mL) on any screening test also underwent ultrasound and repeat blood screening until either the scans suggested an abnormality warranting surgical investigation (ovarian volume greater than 8.8 mL) or the CA 125 level normalized.
During the 8-year study, 717 women had some elevation in CA 125 at some time. "Most of these elevations subsequently returned to normal, and the women are perfectly healthy today," Dr. Jacobs said in an interview with Oncology News International.
A small group had a persistently elevated CA 125 but no abnormality on ultrasound. "We have never found out why. We are still following them to see if cancer develops, either ovarian or possibly breast cancer," he said.